A touch screen is a display that can detect the presence and location of a touch within the display area. The term generally refers to touch or contact with the display of the device by a finger or hand. Touch screens can also sense other passive objects, such as a stylus. A main attribute of a touch screen is that it enables a user to interact with what is displayed directly on the screen, where it is displayed, rather than indirectly with a mouse or touchpad. Such displays can be attached to computers or, as terminals, to networks. They also play a prominent role in the design of digital appliances such as the personal digital assistant (PDA), satellite navigation devices, mobile phones, and video games, etc.